Non-orthogonal amplify-and-forward cooperative diversity based on distributed space-time code

To improve the bandwidth efficiency of the classical orthogonal cooperative transmission scheme while maintaining the cooperative gain, a novel non-orthogonal amplify-and-forward cooperative scheme based on distributed space-time code is proposed. In this scheme, the orthogonal characteristic of Alamouti space-time code is utilized to make cooperative users relay on the shared channel resources so that better bandwidth efficiency can be achieved. Maximum likelihood (ML) and linear detection algorithms are then devised for the destination node. Theoretical and simulation results show that with a specified spectral efficiency, the proposed scheme outperforms the classical scheme in terms of capacity, outage probability and bit error rate (BER) performance.